The present invention relates to lock devices that may lock and unlock an expansion unit which has been loaded into computers body. The expansion units are detachably connectable to such a computer as a notebook personal computer ("PC") to realize a predetermined function.
Portable electronic information terminals, such as notebook PCs, have been required to reduce its size and weight, while demanded to have more functions. The notebook PCs are designed to include a system achieving its functions in an A4-sized, B5-sized, or other portable-sized housing and can, as necessary, be detachably mounted with an expansion unit for changing and extending its capabilities. The expansion units have various structures in accordance with its functions to be added, as seen in a CD-ROM disk drive, a 3.5-inch floppy disk drive, a power supply, an image pick-up device camera unit, a PC card slot, a printer, a scanner, and a network device, etc.
The various expansion units like these are packaged in a housing of a usually common size, and an expansion unit having a necessary function is configured to be attachable to the computer body by inserting it from the housing into the computer body through the side or bottom of the keyboard. Any other necessary function becomes available in the computer by substituting the currently used unit with another one. Many of the expansion units have such a structure as to constitute part of a computer housing when they are loaded into the housing. A lock mechanism is usually provided in the computer housing to lock the expansion unit that has been attached to the housing and to prevent the unit from easily falling off.
FIG. 12 exemplifies a conventional lock device for an expansion unit in a computer. As shown in FIG. 12, the expansion unit 201 works, for example, as a 3.5-inch floppy disk drive into which a 3.5-inch floppy disk may be inserted. The expansion unit 201, which has an approximately rectangular parallelepiped housing, is detachably connectable by sliding it from the side of the computer body. A rear surface 205 of the expansion unit 201 is provided with a connector that is connectable with a connector 206 provided in the computer body. A locking part 203 provided at the bottom portion 200 in the computer body is engageable with a lock groove 204 in the expansion unit 201 where the expansion unit 201 is loaded and the connectors are connected with each other at the rear surface 205. The locking part 203 is a horizontally slidable member, and engageable with the lock groove 204 by a force of a spring at the locking part 203. This engagement fixes the horizontal slides of the expansion unit 201.
This lock device initially moves the locking part 203 against the spring force, when the expansion unit is removed and another expansion unit, e.g., a CD-ROM disk drive is to be attached, and then releases the engagement between the locking part 203 and the lock groove 204, making the expansion unit 201 horizontally slidable, whereby the expansion unit 201 is pushed out in a lateral direction of the computer body and detached from the computer body. A different function of another expansion unit having the same shaped housing is available when the expansion unit is attached to the computer.
This conventional lock device for an expansion unit in a computer requires, when the expansion unit 201 is to be detached, a computer body to be turned upside down so that its bottom may be turned upward or sideward, before releasing the engagement between the locking part 203 and the lock groove 204. Then the locking part 203 is manually manipulated to unlock the expansion unit 201, and the expansion unit 201 is finally detached by sliding the expansion unit 201 along the bottom surface 200.
If the computer body is connected with a cable to a printer, a telephone line to a modem, or the like, or if a child, a handicapped or the like uses the computer, it is not so easy, however to turn the computer body itself upside down or keep it tilted. For example, suppose the computer is tilted to space the bottom from the desk instead of being turned upside down. The expansion unit 201 is manually slid while the manipulation of the locking part is simultaneously required. This inevitable bothhanded manipulation would cause the computer body to drop and get damaged, or too much force applied to the cable or the connector would cause trouble over a signal transmission.